hdf support

1 files changed, 84 insertions, 0 deletions

diff --git a/ebus/datastore.py b/ebus/datastore.py
new file mode 100644
index 0000000..88dcdc9
--- /dev/null
+++ b/ebus/datastore.py
@@ -0,0 +1,84 @@
+#
+
+import os
+from threading import Lock
+import tables
+
+class ValueFloat(tables.IsDescription):
+        timestamp = tables.Time32Col() #index on Time64 is broken on pytables 2.4
+        value = tables.Float32Col()
+
+class ValueInt(tables.IsDescription):
+        timestamp = tables.Time32Col()
+        value = tables.Int32Col()
+
+class ValueString(tables.IsDescription):
+        timestamp = tables.Time32Col()
+        value = tables.StringCol(20)
+
+
+class Datastore(object):
+        def __init__(self,basepath):
+                self.basepath = basepath
+                self.files = {}
+                self.fileLock = Lock()
+                self.tables = {}
+
+        # list all table in a dictionary { path.dot.name : object }
+        def listTables(self):
+                return dict(map(lambda e: (e.title, e), self.file.root))
+
+        def __enter__(self):
+                self.fileLock.__enter__()
+
+        def __exit__(self, *a):
+                self.fileLock.__exit__(*a)
+
+        def getTable(self, name, klass=None):
+                name = name.replace(".","_")
+                with self.fileLock:
+                        if not name in self.files:
+                                path = os.path.join(self.basepath, name+".hdf")
+                                print "open {0}".format(path)
+                                file = tables.openFile(path, "a", title = "eBus Datastore")
+                                self.files[name] = file
+
+                        if not name in self.tables:
+                                t = None
+                                try:
+                                        t = self.files[name].getNode("/"+name)
+                                except tables.NoSuchNodeError,e:
+                                        if not klass: raise e
+                                        t = self.files[name].createTable("/",
+                                                        name,
+                                                        klass,
+                                                        'Description ' + name,
+                                                        filters=tables.Filters(complevel=1),
+                                                        createparents=True)
+                                        t.cols.timestamp.createCSIndex()
+                                self.tables[name] = t
+
+                        return self.tables[name]
+
+        def addValue(self, name, ts, value, klass,flush=False):
+                t = self.getTable(name, klass)
+                with self.fileLock:
+                        t.row['timestamp'] = ts
+                        t.row['value'] = value
+                        t.row.append()
+                        if flush: t.flush()
+
+        def addValueInt(self, name, ts, value): self.addValue(name, ts, value, ValueInt)
+        def addValueString(self, name, ts, value): self.addValue(name, ts, value, ValueString)
+        def addValueFloat(self, name, ts, value): self.addValue(name, ts, value, ValueFloat)
+
+        def flush(self):
+                with self.fileLock:
+                        for file in self.files.values():
+                                file.flush()
+
+        def close(self):
+                with self.fileLock:
+                        for file in self.files.values():
+                                file.close()
+